Decomposition of optimal control in energy minimisation in railway traffic

Abstract

The problem of power cost minimization in railway traction was considered. Since direct solution of this problem is a too extensive task, the problem was decomposed into two problems: 1. Determination of optimum running times of single trains, 2. Determination of station stopping times for all the trains participating in traffic. As the first problem was considered in previous papers, only solution to the second problem was presented in this paper. The methodology presented can be employed for all traction types: steam, diesel-electric, electric d.c. and single-phase electric.

The presented example shows that slight timetable corrections may result in considerable savings in both traction power and electric energy consumption costs as well as significantly more uniform distribution of the loads of transforming substations.

The developed programs and the supporting data base are implementable in any computing center. Highly-automated algorithms require minimum engagement of a user and operator during program running. In view of all the stated points, one may conclude that energy criteria should also be taken into account in railway traffic organization in addition to purely traffic-based criteria. The methodology developed and presented in this paper makes this entirely attainable.